(04.04 MC) When potassium metal is placed in water, a large amount of energy is released as potassium hydroxide and hydrogen gas are produced in the reaction 2K(s) + 2H2O(l) → 2KOH(aq) + H2(g). Your lab partner says this is a redox reaction and a combustion reaction. Do you agree? Defend your answer by explaining whether or not it meets the requirements of each type of reaction. (6 points)

No, this reaction is redox reaction only.

Explanation: Combustion reaction happens when a reactant reacts with oxygen gas producing carbon dioxide. In the reaction, potassium metal does not react with oxygen and does not produce carbon dioxide, so, not a combustion reaction.

Redox Reaction is a reaction that envolves transference of electrons by gaining or losing them.

In the reaction,

→

Potassium metal has an oxidation state of 0. After the reaction, KOH has an oxidation state of +1, so it lost an electron.

Hydrogen has an oxidation state of +1 and after the reaction, its state is 0, which means, it gained 1 electron.

Therefore, the reaction of potassium metal and water is a Redox Reaction.